The invention relates to a punching, stamping rivet including a rivet head, shank, and plural grooves in the shank.
Punching, stamping rivets are used to connect two or more flat workpieces. The shank of the rivet is hereby pressed (punched) through the workpieces forming two punch holes. The lower workpiece, viewed in punching direction, consists of a plastically deformable material, usually a sheet metal. The shank has a shank groove near the shank end. An annular ring is stamped after the punching operation around the shank end into the lower workpiece by a press tool, thus pressing material of the lower workpiece into the shank groove.
The shank groove has in the case of a polygonal rivet a trapezoidal shape in cross section. When workpieces of a hard material are processed, then there exists the danger that the shank will break in the area of the shank groove.
The punching, stamping rivet has a length which corresponds with the desired thickness of both workpieces. When the actual thickness is less than the desired thickness, then not enough material of the lower workpiece is pressed into the shank groove, which affects the strength of the rivet connection.
A further disadvantage of the known punching, stamping rivet is that the desired length of the rivet corresponds with the desired thickness of the adjoining structural parts. When one of the structural parts is significantly thinner than specified, a rivet connection cannot be created.
The purpose is to provide a punching, stamping rivet in such a manner that the aforementioned tolerances in the thickness of the structural parts does not affect the strength of the rivet connection. A further purpose is to provide the punching, stamping rivet in such a manner that materials of varied thicknesses can be processed.